The present invention refers to esters with a mixture of polyhydroxyl alcohols, hexahydrobenzoic acid and a linear carboxylic acid as new industrial products.
The present invention further refers to a process for the preparation of said esters, as well as to their use in the field of lubrication, hydraulic fluids, oily emulsion, and thermal fluids, and in particular to the so-called EP (extreme pressure) fluids.
The use of synthetic lubricants based on long chain, linear aliphatic esters of pelargonic acid, lauric acid, palmitic acid, etc., is known; however, since said acids are of natural origin, their price is relatively high and therefore the lubricating oils obtained therefrom can hardly compete with the mineral oils from oil from an economic viewpoint. Attemps have been also made to obviate this drawback by using e.g. benzoic acid esters which are much cheaper. These esters, however, have not been successful because of a number of drawbacks, such as e.g. that in combustion engines they form partially incombustible products, whereby they produce highly smoky products in the discharge gases. A further drawback is that the lubricating power and especially the viscoelasticity of benzoic acid based esters is relatively not good.